Practically all of them, unfortunately (At the moment)Q83Ia7ta wrote:I'm curious which ones?RealNC wrote:Except for some 240Hz models that have input lag at lower refresh rates.
For example, Leo Bodnar tests show a 3/4 frame delay at the top edge because 240Hz panels currently buffer a slow-scanning 60Hz video signal to a fast-scanning 1/240sec refresh cycle. Basically essentially tantamount of internally converting 60Hz into 240Hz. Even doing that necessarily forces a pre-buffering.
Basically, bottom edge is the same lag regardless but the top edge is lagged (because of the pre-buffering of a slowscan signal onto a fastscan-only panel). Some LCD panels are truly variable speed scan (true multisync in horizontal scanrate) like the BenQ Zowie 1080p 144Hz panels so it certainly is doable.
Proper symmetric scanout (cable scanout = panel scanout symmetry):
VSYNC ON gives +0ms for top edge, +1/2 frame for screen center, and +1 frame for screen bottom.
VSYNC OFF gives symmetric lag +0ms all over the screen
Buffering of Slow Cable Scanout For Fast Panel Scanout:
VSYNC ON can be no better than +((slow scanout) - (fast scanout))ms for top edge, and +0ms for bottom edge, with center being midpoint of two.
VSYNC OFF gains a lag distortion, of the same degree of shift, with top edge being laggier than bottom edge, no matter where tearlines are.
Most modern newer eSports 144Hz monitors have symmetric scanout for 60Hz at the moment. I expect future 240Hz monitors to fix the scanout asymmetry problem for low-Hz signals. Until then, we recommend 240Hz screens be run only at 240Hz at this time -- that's where shine the brightest.
That said, good 240Hz will still do 60Hz less laggier than many 60Hz TVs, but it's not theoretically ideal synchronous cable scanout to panel scanout for equal VSYNC OFF lag throughout the whole screen's surface area.
240Hz is the cat's meow for PC gaming, and may still be above average for consoles, but you might not want them for 60Hz paid-money eSports (e.g. XBox/PS4 eSports) at this time because of (0.75/60)th second more lag for the screen's top edge and (0.375/60)th second more lag than the fastest 60Hz displays for the screen's middle even during VSYNC OFF during 60Hz
Not worried about 60Hz?
Ignore my post, go ahead and buy a 240Hz monitor. Many of us love them for their eSports response (though opinions vary).